AES E-Library

AES E-Library

A Survey of Some New Tubes for Audio Output Applications

Several gaps in the range of available power output levels have been filled in by six (6) recently released tube types, offering a real advantage to the designer of high-fidelity audio equipment: three pentodes, one dual-pentode, and two rectifiers. All of these feature new plate materials and design techniques giving them greater power output capability in the same or smaller envelope size as previously used types. The secret is the new technique of bonding various outer surfaces on the anode such as nickel and aluminum-clad iron to a copper core, which results in excellent surface radiation properties combined with superior heat conductivity. As a result, electrode dissipations can be raised as much as two to one without fear of -hot spots- and overloading.